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Related papers: A Birkhoff-Bruhat Atlas for partial flag varieties

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In this paper we study the Bruhat decomposition of not necessarily connected reductive quasi-split groups $G$ with respect to not necessarily connected parabolic subgroups. If $G$ is defined over a finite field, we construct a smooth…

Algebraic Geometry · Mathematics 2013-12-25 Torsten Wedhorn

In this paper, given a semisimple algebraic group $\bf G$ of rank 2, we construct a special semiorthogonal decomposition in the derived category of coherent sheaves on the flag variety ${\bf G}/{\bf B}$. These decompositions are defined…

Algebraic Geometry · Mathematics 2017-07-18 Alexander Samokhin

In this paper we give a geometric construction of Cherednik's double affine Hecke algebra. We construct the algebra as the equivariant $K$-theory of the Lagrangian subvariety of the cotangent variety of the square of the flag variety of…

q-alg · Mathematics 2016-09-08 H. Garland , I. Grojnowski

We prove that the Schubert structure constants of the quantum $K$-theory ring of any minuscule flag variety or quadric hypersurface have signs that alternate with codimension. We also prove that the powers of the deformation parameter $q$…

Algebraic Geometry · Mathematics 2026-03-24 Anders S. Buch , Pierre-Emmanuel Chaput , Leonardo C. Mihalcea , Nicolas Perrin

Let $G$ be a connected reductive group, and $G/B$ be its flag variety. Let $\pi:G\to G/B$ be the natural projection. In this paper, we developed an algorithm to describe the map $\pi^* :\operatorname{CH}^*(G/B;\mathbb{F}_p)\longrightarrow…

Algebraic Geometry · Mathematics 2021-02-15 Rui Xiong

Horn recursion is a term used to describe when non-vanishing products of Schubert classes in the cohomology of complex flag varieties are characterized by inequalities parameterized by similar non-vanishing products in the cohomology of…

Algebraic Geometry · Mathematics 2011-12-14 Edward Richmond

Let L be a finite field extension of Q_p and let G be the group of L-rational points of a split connected reductive group over L. We view G as a locally L-analytic group with Lie algebra g. We define a functor from admissible locally…

Representation Theory · Mathematics 2016-01-20 Deepam Patel , Tobias Schmidt , Matthias Strauch

We discuss a surprising relationship between the partially ordered set of Newton points associated to an affine Schubert cell and the quantum cohomology of the complex flag variety. The main theorem provides a combinatorial formula for the…

Algebraic Geometry · Mathematics 2020-08-11 Elizabeth Milićević

Let $P$ be a parabolic subgroup in $SL_n(\mathbb C)$. We show that there is a $SL_n(\mathbb C)$-stable closed subvariety of an affine Schubert variety in an infinite dimensional partial Flag variety (associated to the Kac-Moody group…

Algebraic Geometry · Mathematics 2017-05-10 Venkatramani Lakshmibai , Rahul Singh

We initiate the study of K-theory Soergel bimodules-a K-theory analog of classical Soergel bimodules. Classical Soergel bimodules can be seen as a completed and infinitesimal version of their new K-theoretic analog. We show that morphisms…

Representation Theory · Mathematics 2024-02-21 Jens Niklas Eberhardt

Given a certain kind of linear representation of a reductive group, referred to as a quasi-symmetric representation in recent work of \v{S}penko and Van den Bergh, we construct equivalences between the derived categories of coherent sheaves…

Algebraic Geometry · Mathematics 2021-08-02 Daniel Halpern-Leistner , Steven V Sam

Using a blend of combinatorics and geometry, we give an algorithm for algebraically finding all flags in any zero-dimensional intersection of Schubert varieties with respect to three transverse flags, and more generally, any number of…

Algebraic Geometry · Mathematics 2009-09-29 Sara Billey , Ravi Vakil

We give an explicit combinatorial Chevalley-type formula for the equivariant K-theory of generalized flag varieties G/P which is a direct generalization of the classical Chevalley formula. Our formula implies a simple combinatorial model…

Representation Theory · Mathematics 2007-05-23 Cristian Lenart , Alexander Postnikov

Let $G/P$ be a generalized flag variety, where $G$ is a complex semisimple connected Lie group and $P\subset G$ a parabolic subgroup. Let also $X\subset G/P$ be a Schubert variety. We consider the canonical embedding of $X$ into a…

Symplectic Geometry · Mathematics 2009-05-28 Augustin-Liviu Mare

Given a projective variety X and a smooth projective curve C one may consider the moduli space of maps C --> X. This space admits certain compactification whose points are called quasi-maps. In the last decade it has been discovered that in…

Algebraic Geometry · Mathematics 2007-05-23 Alexander Braverman

Let G be a split semisimple linear algebraic group over a field k0. Let E be a G-torsor over a field extension k of k0. Let h be an algebraic oriented cohomology theory in the sense of Levine-Morel. Consider a twisted form E/B of the…

Algebraic Geometry · Mathematics 2016-06-27 Alexander Neshitov , Victor Petrov , Nikita Semenov , Kirill Zainoulline

We exhibit basic algebro-geometric results on the formal model of semi-infinite flag varieties and its Schubert varieties over an algebraically closed field $\mathbb K$ of characteristic $\neq 2$ from scratch. We show that the formal model…

Algebraic Geometry · Mathematics 2024-09-30 Syu Kato

We construct a basis of the equivariant $K$-theory of Bott towers, and we describe precisely the multiplicative structure of these algebras. We deduce similar results for Bott-Samelson varieties. Thanks to the link between flag varieties…

Algebraic Geometry · Mathematics 2007-05-23 Matthieu Willems

Let $G$ be a split semisimple linear algebraic group over a field and let $X$ be a generic twisted flag variety of $G$. Extending the Hilbert basis techniques to Laurent polynomials over integers we give an explicit presentation of the…

Algebraic Geometry · Mathematics 2017-11-01 Sanghoon Baek , Rostislav Devyatov , Kirill Zainoulline

We study a family of polynomials whose values express degrees of Schubert varieties in the generalized complex flag manifold G/B. The polynomials are given by weighted sums over saturated chains in the Bruhat order. We derive several…

Combinatorics · Mathematics 2007-05-23 Alexander Postnikov , Richard P. Stanley